Final answer:
It is generally recommended to replace spatula blades when signs of wear and tear or damage are present, as well as when they become bent, warped, or develop discoloration or odors.
Step-by-step explanation:
In general, spatula blades should be replaced when they show signs of wear and tear or damage. This can vary depending on the material of the spatula and frequency of use. For example, plastic spatula blades may need to be replaced more often than those made of silicone or metal.
It is important to check the condition of the blade regularly. Look for any cracks, chips, or fraying edges. If the blade becomes bent or warped, it may not function properly and should be replaced.
Additionally, if the spatula blade starts to discolor or develop a foul odor that cannot be removed with cleaning, it is a good indication that it should be replaced as well.